Forgive me for having an opinion, but I'd prefer BCs rather bug-free Heroics over MoPs insanely boring, RP-filled excuses for "Heroics" any day of the week. I never had any issues with bugs in BC heroics, besides Thrall occasionally becoming unresponsive at the end of Old Hillsbrad, which was, admittedly, fucking annoying, since that was without question the hardest heroic the game has ever seen.
Sure, quantity isn't always better than quality, but what exactly is better in "quality" about MoPs heroics? Sure, there's more scripted events, but can you honestly argue that they're for the betterment of the dungeon experience?
I mean, would you enjoy Shado-Pan less if they removed those goddamned jumping apprentice Pandas from the room after the frost arrows gauntlet? I certainly wouldn't. Would you enjoy Stormstout Brewery less if the dungeon was less about fighting thousands of Jazz Jackrabbits and getting Ooked in the Dook on a regular basis? Would you enjoy Gates of the Setting Sun less if you didn't have to stand around for 5 minutes while absurdly easy explosive mantids came at you 1 at a time?
I'd be very surprised if you answered "yes" to any of the aforementioned questions.
Perhaps if they spent a little less time scripting such fucking awful events, and more into actually creating instances, we'd have not only a greater variety of dungeons, but less tedious ones too. A win-win situation, so to speak.
As for me, I'm a greedy one - I'd rather have a huge variety of dungeons AND constantly added ones every patch - but if they actually ARE going to add regular new ones, I'll settle for that. I'll believe it when I see it, however.